Bob Holdsworth is the founder and leader of the Reactivation Research Group (RRG) in Durham Earth Sciences. He is the leading international authority on the nature, causes and significance of fault reactivation during lithosphere deformation. He is also well-known internationally for his work in two other areas: oblique tectonics (transpression/transtension) and folding patterns in shear zones. Most recently, he has been instrumental in establishing Durham RRG as a leading international group in the area of GPS-based digital capture of geological field data, its visualisation and analysis using GIS. In 2005, this led to the setting-up of the Durham Centre for Terrestrial Laser Scanning (CeTLS).